Hi Lost...I was a WAW, and like you, I had tried to get my now-ex-husband to see and understand that I needed more from him or I would slip away.
In the end, he just couldn't or wouldn't give me enough.
I had been unfaithful in the past, but at the time I finally separated from him, there was no OM. I did however, quickly begin dating once I moved out.
You can go to my screen name, click "view posts", and go to the first post called "new here" if you want to read my whole tale (its pretty long).
My advice to you is this: if you get divorced and stay with the OM, it will not work out. No matter how you think it may work out at this time, it won't. Please do some research about marriages which started as an affair and the likelihood that they stay together. I know you aren't saying you are going to marry the OM, but just so you know those statistics, you should go and do the research.
When a relationship starts out as an affair, no matter what you may tell yourself about how you were already "done" with the marriage, you will find later that it just doesn't work that way. The mind, the psyche, and your inner self, all KNOW better than the half-truths you are telling yourself. (Please don't think I am judging you here - this is just the truth, not a lecture). If you end up divorced, and you go directly into the arms of another man without healing yourself and regaining your autonomy and having some freedom and dating some other men first...then you will likely leave the OM within one year, or if you stay with him, you will likely have an affair on him, too (or he may have one on you).
As for you and your husband...you have to get your head on straight before you can really know whether or not your marriage still has a chance to survive. You can't get it on straight when there is an OM.
Again, this is not judgement. It is simply the truth, and I have lived it so I am speaking from a position of knowlege.
